Detection and quantification of gasping during resuscitation for out-of-hospital cardiac arrest

Agonal breathing upon hospital arrival as a prognostic factor in patients experiencing out-of-hospital cardiac arrest

Background

Agonal breathing is a relatively common symptom that follows cardiac arrest when the brainstem function is preserved. Agonal breathing is associated with favorable survival in patients experiencing out-of-hospital cardiac arrest (OHCA). While previous studies focused on agonal breathing observed in the pre-hospital setting for all study subjects, we focused on agonal breathing observed upon hospital arrival. In this multicenter prospective study, we aimed to assess the prognosis of patients exhibiting agonal breathing upon hospital arrival were compared. We hypothesized that agonal breathing at hospital arrival would be associated with favorable neurological outcomes among patients with OHCA.

Methods

The data on incidence of agonal breathing were prospectively collected for all evaluable participants in a multicenter, observational study in Japan (SOS-KANTO [Survey of Survivors after Out-of-Hospital Cardiac Arrest in Kanto Area] 2017 Study). Groups with and without agonal breathing were compared upon hospital arrival. Propensity-score with inverse probability of treatment weighting (IPTW) analysis was performed to adjust for confounding factors. The primary outcome was a favorable neurological outcome (Cerebral Performance Category 1-2) at 1 month.

Results

A total of 6,457 participants out of the 9,909 registered in SOS-KANTO 2017 (in which 42 facilities participated) were selected for the current study. There were 128 patients (2.0%) in the with-agonal breathing group and 6,329 (98.0%) in the withoutagonal breathing group. The primary outcome was 1.1% in the with-agonal breathing group and 0.6% in the without-agonal breathing group (risk difference, 0.55; 95% confidence interval, 0.23-0.87) after IPTW analysis.

Conclusion

In this multicenter prospective study, agonal breathing at hospital arrival was significantly associated with better neurological outcomes and increased survival at 1 month. Thus, agonal breathing at hospital arrival may be a useful prognostic predictor for patients experiencing OHCA.

Out-of-Hospital Cardiac Arrest in the Eye of the Beholder and Emergency Medical Service

Purpose

Out-of-hospital cardiac arrest (OHCA) remains a global healthcare problem, with low survival and bystander cardiopulmonary resuscitation (CPR) rates. This study aimed to identify event-related factors in OHCA and their impact on return of spontaneous circulation (ROSC) achievement and maintenance until hospital admission.

Patients and Methods

All data were collected from Utstein Resuscitation Registry Template for OHCA from The Institute of Emergency Medicine of Zagreb from January 2012 to August 2022. This cross-sectional research analyzed 2839 Utstein reports, including 2001 male, 836 female, and 8 subjects of unknown gender. The average age was 65.4 ± 16.2 years.

Results

The most frequent place of collapse was private residence, and 27% of collapses were unwitnessed. Dispatcher-provided CPR instructions were provided in 39.7% of cases until the arrival of the emergency service team, which showed a very strong effect on bystander-provided CPR, and were followed in 68.4% of cases, while non-instructed bystander CPR was provided in only 7.9% of cases. Bystander CPR is more likely to be provided in public places than in private residences, often with both compression and ventilation. Bystander CPR was also more likely to be provided to men. Cases with bystander CPR, and compressions with ventilation compared to compression only CPR, showed a significantly greater success in maintaining ROSC later in CPR, both with moderate effects.

Conclusion

Bystander CPR has been shown to have a significant role in achieving and maintaining ROSC until hospital admission. However, our results showed a location-dependent nature of bystanders' willingness to perform CPR as well as sex disparities in patients receiving CPR. With deficient education in basic life support in Croatia, dispatchers need to insist on and instruct bystander CPR performance.

Intrathoracic Pressure Regulator Performance in the Setting of Hemorrhage and Acute Lung Injury

INTRODUCTION

Intrathoracic pressure regulation (ITPR) can be utilized to enhance venous return and cardiac preload by inducing negative end expiratory pressure in mechanically ventilated patients. Previous preclinical studies have shown increased mean arterial pressure (MAP) and decreased intracranial pressure (ICP) with use of an ITPR device. The aim of this study was to evaluate the hemodynamic and respiratory effects of ITPR in a porcine polytrauma model of hemorrhagic shock and acute lung injury (ALI).

METHODS

Swine were anesthetized and underwent a combination of sham, hemorrhage, and/or lung injury. The experimental groups included: no injury with and without ITPR (ITPR, Sham), hemorrhage with and without ITPR (ITPR/Hem, Hem), and hemorrhage and ALI with and without ITPR (ITPR/Hem/ALI, Hem/ALI). The ITPR device was initiated at a setting of -3 cmH2O and incrementally decreased by 3 cmH2O after 30 minutes on each setting, with 15 minutes allowed for recovery between settings, to a nadir of -12 cmH2O. Histopathological analysis of the lungs was scored by blinded, independent reviewers. Of note, all animals were chemically paralyzed for the experiments to suppress gasping at ITPR pressures below -6 cmH2O.

RESULTS

Adequate shock was induced in the hemorrhage model, with the MAP being decreased in the Hem and ITPR/Hem group compared with Sham and ITPR/Sham, respectively, at all time points (Hem 54.2 ± 6.5 mmHg vs. 88.0 ± 13.9 mmHg, p < 0.01, -12 cmH2O; ITPR/Hem 59.5 ± 14.4 mmHg vs. 86.7 ± 12.1 mmHg, p < 0.01, -12 cmH2O). In addition, the PaO2/FIO2 ratio was appropriately decreased in Hem/ALI compared with Sham and Hem groups (231.6 ± 152.5 vs. 502.0 ± 24.6 (Sham) p < 0.05 vs. 463.6 ± 10.2, (Hem) p < 0.01, -12 cmH2O). Heart rate was consistently higher in the ITPR/Hem/ALI group compared with the Hem/ALI group (255 ± 26 bpm vs. 150.6 ± 62.3 bpm, -12 cmH2O) and higher in the ITPR/Hem group compared with Hem. Respiratory rate (adjusted to maintain pH) was also higher in the ITPR/Hem/ALI group compared with Hem/ALI at -9 and - 12 cmH2O (32.8 ± 3.0 breaths per minute (bpm) vs. 26.8 ± 3.6 bpm, -12 cmH2O) and higher in the ITPR/Hem group compared with Hem at -6, -9, and - 12 cmH2O. Lung compliance and end expiratory lung volume (EELV) were both consistently decreased in all three ITPR groups compared with their controls. Histopathologic severity of lung injury was worse in the ITPR and ALI groups compared with their respective injured controls or Sham.

CONCLUSION

In this swine polytrauma model, we demonstrated successful establishment of hemorrhage and combined hemorrhage/ALI models. While ITPR did not demonstrate a benefit for MAP or ICP, our data demonstrate that the ITPR device induced tachycardia with associated increase in cardiac output, as well as tachypnea with decreased lung compliance, EELV, PaO2/FIO2 ratio, and worse histopathologic lung injury. Therefore, implementation of the ITPR device in the setting of polytrauma may compromise pulmonary function without significant hemodynamic improvement.

Compression asphyxia and other clinicopathological findings from the Hillsborough Stadium disaster

Ninety-six people died following a crowd crush at the Hillsborough Football Stadium, Sheffield, UK in 1989. The cause of death in nearly all cases was compression asphyxia. The clinical and pathological features of deaths encountered in crowds are discussed with a particular focus on the Hillsborough disaster.

Prognostic value of gasping for short and long outcomes during out-of-hospital cardiac arrest: an updated systematic review and meta-analysis

Objective

We systematically reviewed the literature to investigate whether gasping could predict short and long outcomes in patients with out of hospital cardiac arrest (OHCA).

Methods

PubMed, Embase, and Cochrane Library were searched for observational studies regarding the prognostic effect of gasping on short and long outcomes in adults with OHCA. The primary outcome was return of spontaneous circulation (ROSC). The secondary outcomes were favorable neurological outcome at discharge or at 30 days after cardiac arrest;long term (≥6 months) survival; initial shockable rhythm.The Mantel-Haenszel method with random-effects model was used to calculate pooled relative risks (RRs) and 95% confidence intervals (CIs).

Results

Five studies (six cohorts) were included in the final analysis. In the pooled analysis, gasping was not only associated with a significant increase in ROSC (RR, 1.87; 95% CI, 1.64–2.13; I² = 70%), but also a high likelihood of favorable neurological outcomes (RR, 3.79; 95% CI, 1.86–7.73), long-term survival (RR, 3.46; 95% CI, 1.70–7.07), and initial shockable rhythm (RR, 2.25; 95% CI, 2.05–2.48).

Conclusions

Current evidence indicates that gasping can predict short and long outcomes in patients with OHCA.In addition, gasping is associated with a high likelihood of initial shockable rhythm,which may contribute to positive outcomes.

Bystander-witnessed cardiac arrest is associated with reported agonal breathing and leads to less frequent bystander CPR

AIM

Although the importance of bystander cardiopulmonary resuscitation has been shown in multiple studies, the rate of bystander cardiopulmonary resuscitation is still relatively low in many countries. Little is known on bystanders' perceptions influencing the decision to start cardiopulmonary resuscitation. Our study aims to determine such factors.

MATERIALS AND METHODS

Semi-structured telephone interviews with bystanders of out-of-hospital cardiac arrests between December 2014 and April 2016 were performed in a prospective manner. This single-center survey was conducted in the city of Münster, Germany. The bystander's sex and age, the perception of the victim's breathing and initial condition were correlated with the share of bystander cardiopulmonary resuscitation in the corresponding group.

RESULTS

101 telephone interviews were performed with 57 male and 44 female participants showing a mean age of 52.7 (SD ± 16.3). In case of apnoea 38 out of 46 bystanders (82.6%) started cardiopulmonary resuscitation; while in case of descriptions indicating agonal breathing 19 out of 35 bystanders (54.3%) started cardiopulmonary resuscitation (p = .007). If the patient was found unconscious 47 out of 63 bystanders (74.7%) performed cardiopulmonary resuscitation, while in cases of witnessed cardiac arrest 19 out of 38 bystanders (50%) attempted cardiopulmonary resuscitation (p = .012). Witnessed change of consciousness is an independent factor significantly lowering the probability of starting cardiopulmonary resuscitation (regression coefficient -1.489, p < .05).

CONCLUSION

The witnessed loss of consciousness was independently associated with a significant reduction in the likelihood that bystander-CPR was started. These data reinforce the importance of teaching the recognition of early cardiac arrest.

Chest compressions during ventilation in out-of-hospital cardiac arrest cause reversed airflow

AIM

During cardiopulmonary resuscitation, once the patient is intubated, compressions and ventilations are performed simultaneously. Chest compressions during the inspiratory phase of ventilation may force air out of the lungs, causing so-called "reversed airflow", which may lead to ineffective ventilation. The purpose of this study is to determine the occurrence of this phenomenon and to quantify the volume of reversed airflow.

METHODS

Observational study. During manual ventilation of intubated patients receiving chest compressions, the pressure gradient over the endotracheal tube was measured using two air-filled catheters connected to a custom-made portable device. Chest compression data were measured using an accelerometer on a Zoll E- series defibrillator. All data are reported as mean (standard deviation; range).

RESULTS

Twenty-five patients and a total of 368 ventilations were studied, on average 15 (6; 10-30) per patient. The mean tidal volume, minute volume and ventilation rate were respectively 690 ml (160; 240-1260), 10.5 l/min (4.8; 4.4-22.1) and 18/min (6; 6-35). Reversed airflow was observed in 21/25 patients (84%) and in 65% of all ventilations, with on average two episodes per ventilation. Fifty-five percent of the chest compressions during the inspiratory phase of the ventilation generated reversed airflow. The mean volume of the reversed airflow was 96 ml per episode (52; 12-364).

CONCLUSION

Chest compressions during ventilation in intubated patients generated reversed airflow in most patients. There was wide variation in the number of episodes and volume of the reversed airflow between patients. The effect of this phenomenon on the efficacy of ventilation during resuscitation and on outcome needs further investigation.